Metadata#

  • GUID: {988c59c5-0a1c-45b6-a555-0c62276e327d}
  • Provider: Microsoft-Windows-SMBClient

Address Fields#

The Address, RemoteAddress, or LocalAddress fields found in Event IDs such as 30804, 30803, 30806, 30833, etc., use a built-in structure to represent IP socket addresses. When leveraging or analyzing these events (especially for detection engineering), it's useful to understand how these fields are encoded. This format embeds the address family, port number, and IP address, with some padding / reserved fields.

SOCKADDR_IN (IPv4)#

typedef struct sockaddr_in {
#if ...
  short          sin_family;
#else
  ADDRESS_FAMILY sin_family;
#endif
  USHORT         sin_port;
  IN_ADDR        sin_addr;
  CHAR           sin_zero[8];
} SOCKADDR_IN, *PSOCKADDR_IN;

SOCKADDR_IN6_LH (IPv6)#

typedef struct sockaddr_in6 {
  ADDRESS_FAMILY sin6_family;
  USHORT         sin6_port;
  ULONG          sin6_flowinfo;
  IN6_ADDR       sin6_addr;
  union {
    ULONG    sin6_scope_id;
    SCOPE_ID sin6_scope_struct;
  };
} SOCKADDR_IN6_LH, *PSOCKADDR_IN6_LH, *LPSOCKADDR_IN6_LH;

For IPv4 (AF_INET)#

SOCKADDR_IN

Bytes (offset)LengthDescription
00–012Address family (usually 02 00 for IPv4)
02–032Port (little endian)
04–074IPv4 address (big endian)
08–158Padding / Reserved

For IPv6 (AF_INET6)#

SOCKADDR_IN6_LH

Bytes (offset)LengthDescription
00–012Address family (17 00 for IPv6)
02–032Port (little endian)
04–074Flow info or padding
08–2316IPv6 address (big endian)
24–2716Scope ID

Examples#

IPv4 Example#

Field (hex):

02 00 BD 01 0A 00 00 01 00 00 00 00 00 00 00 00

Decoded:

  • Address family: 02 00 → IPv4
  • Port: BD 010x01BD = 445
  • IP Address: 0A 00 00 0110.0.0.1
  • Padding: 8 null bytes

Results: 10.2.0.50:445

IPv6 Loopback#

Field (hex):

17 00 BD 01 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00

Decoded:

  • Address family: 17 00 → IPv6
  • Port: BD 01445
  • IPv6: 0000:0000:0000:0000:0000:0000:0000:0001[::1]

Results: [::1]:445

Field (hex):

17 00 BD 01 00 00 00 00 FE 80 00 00 00 00 00 00 76 E4 CE 6A 17 77 4C AA 0B 00 00 00

fe80::210:5aff:feaa:20a2

Decoded:

  • Address family: 17 00 → IPv6
  • Port: BD 01445
  • IPv6: fe80::76e4:ce6a:1777:4caa

Results : [fe80::76e4:ce6a:1777:4caa]:445

Common IPv4 Address Ranges in Hex#

IP PrefixExample AddressEncoded (hex bytes 4–7)
10.10.0.0.10A 00 00 01
127.127.0.0.17F 00 00 01
169.254.169.254.0.1A9 FE 00 01
172.172.16.0.1AC 10 00 01
192.168.192.168.1.1C0 A8 01 01

Related Articles

Other threads in the archive worth reading next.